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Hemispherical digital photographs offer advantages over conventional methods for quantifying pathogen-mediated changes caused by infestation of Phytophthora cinnamomi

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Abstract

Estimates of canopy closure using hemispherical digital images, canopy cover using a point-intercept method, ground cover, number of plant species and total plant species cover were used to quantify the impact of Phytophthora cinnamomi in disease centres in Banksia shrubland, Banksia woodland and Eucalyptus marginata forest biomes of the South-West Botanical Province of Western Australia. Estimates of the time required to capture and analyse data and correlations were used to contrast the five methods. For canopy closure or cover, hemispherical digital images were on average, seven times faster to capture and analyse than the point-intercept method. For both canopy closure and ground cover, mean values from three point samples were not significantly different to mean values from transects across the disease front. Differences in canopy closure and ground cover between biomes and disease obtained from point sampling showed the same trends as transects. Canopy closure differed significantly between biome, being greatest for E. marginata forest, least for Banksia shrubland and intermediate for Banksia woodland. Ground cover was greatest for Banksia shrubland, least for E. marginata forest and intermediate for Banksia woodland. For all biomes there was significantly less canopy closure in diseased than adjoining healthy areas. There was no significant difference in ground cover between diseased and adjoining healthy areas of Banksia shrubland, but significantly less ground cover in diseased than adjoining healthy areas in the Banksia woodland and E. marginata forest. Canopy closure and ground cover are likely measuring different aspects of the impact of P. cinnamomi and, therefore, both should be measured when determining pathogen-mediated changes. Advantages of using hemispherical digital images over the other methods for determining temporal and spatial changes associated with P. cinnamomi infestation are discussed.

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References

  • Bunnell FL, Vales DJ (1990) Comparison of methods for estimating forest overstory cover: differences among techniques. Canadian Journal of Forest Research 20, 101–107.

    Article  Google Scholar 

  • Campbell GS, Norman JM (1998) ‘An introduction to environmental biophysics.’ (Springer-Verlag: New York)

    Google Scholar 

  • Chan SS, McCreight RW, Walstad JD, Spies TA (1986) Evaluating forest vegetation cover with computerized analysis of fisheye photographs. Forest Science 32, 1085–1091.

    Google Scholar 

  • Chen JM, Black TA, Adams RS (1991) Evaluation of hemispherical photography for determining plant area index and geometry of a forest stand. Agricultural and Forest Meteorology 56, 129–143. doi: 10.1016/0168-1923(91)90108-3

    Article  CAS  Google Scholar 

  • Cormeau P (2000) Measuring light in the forest. Extension Note 42. British Columbia Ministry of Forests Research Branch, Victoria.

    Google Scholar 

  • Easter MJ, Spies TA (1994) Using hemispherical photography for estimating photosynthetic photon flux density under canopies and in gaps in Douglas-fir forests of the Pacific Northwest. Canadian Journal of Forest Research 24, 2050–2058.

    Article  Google Scholar 

  • Evans GC, Coombe DE (1959) Hemispherical and woodland canopy photography and the light climate. Journal of Ecology 47, 103–113. doi: 10.2307/2257250

    Article  Google Scholar 

  • Fiala ACS, Garman SL, Gray AN (2006) Comparison of five canopy cover estimation techniques in the western Oregon Cascades. Forest Ecology and Management 232, 188–197. doi: 10.1016/j.foreco.2006.05.069

    Article  Google Scholar 

  • Frazer GW, Canham CD, Letzman KP (1999) ‘Gap Light Analyzer (GLA): imaging software to extract canopy structure and gap light transmission indices from true-colour fisheye photographs. Users manual and program documentation, Version 2.0.’ (Simon Fraser University: Burnaby, British Columbia, and the Institute of Ecosystem Studies: Millbrook, NY)

    Google Scholar 

  • Grant M, Barrett S (2003) The distribution and impact of Phytophthora cinnamomi Rands in the south coast region of Western Australia. In ‘Phytophthora in forests and natural ecosystems. 2nd international IUFRO working party 7.02.09 meeting, Albany, Western Australia’. (Eds JA McComb, GEStJ Hardy, IC Tommerup) pp. 34–40. (Murdoch University Print: Murdoch)

    Google Scholar 

  • Jennings SB, Brown MD, Sheil D (1999) Assessing forest canopies and understory illumination: canopy closure, canopy cover and other measures. Forestry 72, 59–73. doi: 10.1093/forestry/72.1.59

    Article  Google Scholar 

  • Kennedy J, Weste G (1986) Vegetation changes associated with invasion by Phytophthora cinnamomi on monitored sites in the Grampians, Western Victoria. Australian Journal of Botany 34, 251–279. doi: 10.1071/BT9860251

    Article  Google Scholar 

  • Kirby KN (1993) ‘Advanced data analysis with SYSTAT.’ (Van Nostrad Reinhold: New York)

    Google Scholar 

  • Laidlaw WS, Wilson BA (2003) Floristic and structural characteristics of a coastal heathland exhibiting symptoms of Phytophthora cinnamomi infestation in the eastern Otway Ranges, Victoria. Australian Journal of Botany 51, 283–293. doi: 10.1071/BT02100

    Article  Google Scholar 

  • Lowman MD, Nadkarni NM (1995) ‘Forest canopies.’ (Academic Press: San Diego, CA)

    Google Scholar 

  • Martens SN, Ustin SL, Rousseau RA (1993) Estimation of tree canopy leaf area index by gap fraction analysis. Forest Ecology and Management 61, 91–108. doi: 10.1016/0378-1127(93)90192-P

    Article  Google Scholar 

  • McCarthy J (2001) Gap dynamics of forest trees: a review with particular attention to boreal forests. Environment Review 9, 1–59. doi: 10.1139/er-9-1-1

    Article  Google Scholar 

  • McDougall KL (1997) Vegetation patterns in the northern jarrah forest of Western Australia in relation to dieback history and the current distribution of Phytophthora cinnamomi. PhD Thesis, Murdoch University, Western Australia.

    Google Scholar 

  • Newell GR (1998) Characterisation of vegetation in an Australian open forest community affected by cinnamon fungus (Phytophthora cinnamomi): implications for faunal habitat quality. Plant Ecology 137, 55–70. doi: 10.1023/A:1008056432001

    Article  Google Scholar 

  • Nutter FW Jr, Gleason ML, Jenco JH, Christians NC (1993) Assessing the accuracy, intra-rater repeatability, and inter-rater reliability of disease assessment systems. Phytopathology 83, 806–812. doi: 10.1094/Phyto-83-806

    Article  Google Scholar 

  • Pickett STA (1987) Space-for-time substitution as an alternative to long-term studies. In ‘Long-term studies in ecology. Approaches and alternatives’. (Ed. GE Likens) pp. 110–135. (Springer-Verlag: New York)

    Google Scholar 

  • Rautiainen M, Stenberg P, Nilson T (2005) Estimating canopy cover in scots pine stands. Silva Fennica 39, 137–142.

    Google Scholar 

  • Rich PM, Clark DB, Clark DA, Oberbauer SF (1993) Long-term study of solar radiation in a tropical wet forest using quantum sensors and hemispherical photography. Agricultural and Forest Meteorology 74, 237–249.

    Google Scholar 

  • Roxburgh JR, Kelly D (1995) Uses and limitations of hemispherical photography for estimating forest light environments. New Zealand Journal of Ecology 19, 213–217.

    Google Scholar 

  • Shearer BL (1994) The major plant pathogens occurring in native ecosystems of south-western Australia. Journal of the Royal Society of Western Australia 77, 113–122.

    Google Scholar 

  • Shearer BL, Dillon M (1995) Susceptibility of plant species in Eucalyptus marginata forest to infection by Phytophthora cinnamomi. Australian Journal of Botany 43, 113–134. doi: 10.1071/BT9950113

    Article  Google Scholar 

  • Shearer BL, Dillon M (1996) Impact and disease centre characteristics of Phytophthora cinnamomi infestations of Banksia woodland on the Swan Coastal Plain,Western Australia. Australian Journal of Botany 44, 79–90. doi: 10.1071/BT9960079

    Article  Google Scholar 

  • Shearer BL, Hill TC (1989) Diseases of Banksia woodlands on the Bassendean and Spearwood Dune Systems. Journal of the Royal Society of Western Australia 71, 113–114.

    Google Scholar 

  • Shearer BL, Tippett JT (1989) Jarrah dieback: the dynamics and management of Phytophthora cinnamomi in the jarrah (Eucalyptus marginata) forest of south-western Australia. Research Bulletin 3. Department of Conservation and Land Management, Perth, Western Australia.

    Google Scholar 

  • Shearer BL, Crane CE, Cochrane A (2004) Quantification of the susceptibility of the native flora of the South-West Botanical Province, Western Australia, to Phytophthora cinnamomi. Australian Journal of Botany 52, 435–443. doi: 10.1071/BT03131

    Article  Google Scholar 

  • Shearer BL, Crane CE, Barrett S, Cochrane A (2007) Phytophthora cinnamomi invasion, a major threatening process to flora diversity conservation in the south-west botanical province of Western Australia. Australian Journal of Botany 55, 225–238. doi: 10.1071/BT06019

    Article  Google Scholar 

  • Weste G (1986) Vegetation changes associated with invasion by Phytophthora cinnamomi of defined plots in the Brisbane ranges, Victoria, 1975–1985. Australian Journal of Botany 34, 633–648. doi: 10.1071/BT9860633

    Article  Google Scholar 

  • Whitford KM, Colquhoun IJ, Lang ARG, Harper BM (1995) Measuring leaf area index in a sparse eucalypt forest: a comparison from direct measurement, hemispherical photography, sunlight transmittance and allometric regression. Agricultural and Forest Meteorology 74, 237–249. doi: 10.1016/0168-1923(94)02189-Q

    Article  Google Scholar 

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Crane, C.E., Shearer, B.L. Hemispherical digital photographs offer advantages over conventional methods for quantifying pathogen-mediated changes caused by infestation of Phytophthora cinnamomi . Australasian Plant Pathology 36, 466–474 (2007). https://doi.org/10.1071/AP07052

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